title: Effects of a tryptophan supplemented diet and U.V. radiation on the rat lens.
abstract: Rats maintained on a tryptophan supplemented diet and exposed to U.V. radiation showed decreased concentration of ascorbic acid in serum. In the lens, a small increase in the urea-mercaptoethanol soluble fraction was observed suggesting some oxidation of P-SH groups. The decreased concentrations of lens glutathione and ascorbic acid were accompanied with increased concentration of malondialdehyde suggesting increased oxidative stress. The activities of glutathione peroxidase decreased by about 40%. Though the activity of glutathione reductase decreased by about 58%, addition of FAD in the enzyme assay system showed restoration of lost activity. Additive effect of raised serum tryptophan concentration and ultraviolet radiation in causing damage to the eye lens is suggested.
authors.affiliation: Ocular Biochemistry Section, Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, Ansari Nagar, New Delhi.
authors.forename: R L
authors.initials: RL
authors.lastname: Mathur
authors.forename: P
authors.initials: P
authors.lastname: Sahai
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D003459:Crystallins / Q000378:metabolism; D004032:Diet; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007908:Lens, Crystalline / Q000201:enzymology / Q000528:radiation effects*; D008315:Malondialdehyde / Q000378:metabolism; D010734:Phosphogluconate Dehydrogenase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014364:Tryptophan / Q000378:metabolism / Q000494:pharmacology*; D014466:Ultraviolet Rays; D014508:Urea / Q000378:metabolism
chemical_list: D003459:Crystallins; D008315:Malondialdehyde; D014364:Tryptophan; D014508:Urea; D010734:Phosphogluconate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione; D001205:Ascorbic Acid